It later retweeted a similar tweet from Israel-hater Asa Winstanley, who had indulged in antisemitic tropes against Ms Mirwitch.

To this, Ms Mirwitch responded: “Asa accused me of belonging to a front group for the Israeli embassy, just because I’m Jewish. I utterly oppose the Israeli government.

“It’s upsetting that comrades on the Young Labour committee have decided it’s appropriate to RT him, on a week when I’ve received antisemitic abuse.”

She also tweeted to make “crystal clear” that the tweets about Ms Ryan were not hers, as she also controls the account.

She added: “Multiple members of YL committee have access to the account.

“I’ll never stop fighting for an open, inclusive and welcoming Young Labour.”

When asked why she didn’t remove the tweet as chairman of the group, she replied: “I don’t have that power. I will try, but I will be outvoted by my committee.

“I’m privileged and proud to have been democratically elected by Young Labour members.

“The actions of a few on social media don’t represent the vast majority of activists. I’m not going to resign and I’m not going anywhere.

“I will fight for this movement and fight against hate.”

Later, almost 300 Labour activists signed an open letter calling for action.

It said: “We demand a change to how the Young Labour social media portfolio is managed to ensure that our collective reputation is not damaged by a select few who, some could argue, are actually damaging our party’s chances at getting into government, not helping it.”

Abdi Duale, a former Labour staff member and Young Fabians executive, shared the open letter, adding: “The Young Labour Twitter account has been an absolute disgrace, Miriam and a handful of others have tried to keep it inclusive, but others on the committee have time and time again sought to create divisions in our party.”